Brush rings or disk brushes are known, for example, from DE 39 14 745 A1 and corresponding U.S. Pat. No. 4,998,316 issued Mar. 12, 1991. They have a substantially circular frame on which radially outwardly protruding bristles are arranged. To form a sweeping roller, several such disk brushes are slid onto a rotatably mounted shaft, and are non-rotatably connected to the rotatable shaft.
To produce such disk brushes, it is provided, for example, to supply wires or similar bristle material, cut to length, successively to an extruder by way of an end portion in order to provide the ends with a thermoplastic material. The bristle bands prefabricated in this manner can then be bent into a ring-shaped form and then, in particular before a final cooling of the thermoplastic compound, can be pressed into their final, for example, circular form.
The most varied geometries of disk brushes and brush rings exist. The brush ring, which lies radially on the inside and accommodates the bristles, can, for example, have an extensively planar, but also a zigzag-shaped structure. Such zigzag-shaped or wavy structures contribute to a uniform bristle density on the outer circumference of the sweeping roller. Scoring on the substrate to be cleaned can also be counteracted by a zigzag or wave profile.
EP 1 009 254 B1 and corresponding U.S. Pat. No. 6,205,609 B1 issued Mar. 27, 2001, make known a further brush ring which is produced completely from recyclable production material and where the circumference of the frame part has been arranged in order to project at least two points with substantially flat side surfaces laterally of a bottom base. With the brush rings abutting directly against one another in the axial direction, the substantially flat side surfaces are in direct contact with one another such that, when a sweeping roller is operating, the individual brush rings do not start to vibrate.
In the transition between the substantially flat side surfaces, the previously known frame part has in each case really clearly pronounced kinks which, in the case of extreme mechanical stress, provide a weak point in the operation of the brush disk. There can be cracking or even fractures in the region of these types of kinks in the frame part.
In addition, EP 1 647 201 B1 published Sep. 5, 2007, makes known a brush ring arrangement, the core of which has several portions which are stepped in the axial direction, realized in a substantially even manner and also merge into one another by means of really concisely realized kinks.
Finally, WO 2005/034678 A1 discloses a substantially even brush ring, on the inside of which individual projections are integrally formed which, however, when viewed in the axial direction, extend within the extension of the bundle of bristles arranged on the frame.
Common to all the brush rings known currently is that they are to be connected in a non-rotatable manner to the shaft which accommodates them. Amongst themselves, however, the brush rings, which come to abut against one another, have no direct connection to one another.
Consequently, it is the object of the present invention to provide a brush ring for a sweeping roller which has improved mechanical characteristics, which can be fastened to a shaft in a universal manner and in different configurations and which, where possible, bestows on the sweeping roller a greater degree of stability.
At the same time, the aim of the present invention is to improve and to simplify the assembly and disassembly of brush rings on a rotatable shaft and also the manageability of the brush rings as semi-finished products.